Processing

Before presenting the different sections of the processing unit, is important to have an overall idea of how they are interconnected. The following diagram gives a summary outline of Gota Verdes` extended biofuel chain. The main idea is to maximize all the products and by-products, by making ample use of all possible value added locally.

Integrated biofuel chain in the Gota Verde Project

Click to enlarge

 

Postharvest

Different crops have different post-harvest processes. In this section, we simply describe the post-harvest process in the case of Jatropha.

During harvest, fruits colored yellow, brown and black are plucked from the stem. The fruits are transported to 6 collection centers (see below), in which records on the amount of fruits delivered by farmers are keep. Later on, the fruits undergo a post-harvest treatment. The collection centers, set up in the second half of 2008, are located at strategic positions within the production area.

  

At the collection centers, the seeds undergo three main stages of post-harvest treatment:

(a) Shelling/ Dehusking (separation of seeds of the fruit)
(b) Drying (basically with the use of solar energy directly from the sun)
(c) Transportation of seeds  (to the facilities of BYSA)

Furthermore, some trials shall be carried out with seeds collected locally from live fences.

Key institutions involved in the sub-component "Post-harvest" are:
BYSA (implementation)
CEVER (production of the Universal Nut Sheller)

This component is co-funded by:

Everts Firm (LINK: www.evertsgroningen.nl), Netherlands. This firm shall contribute to the designing and construction of a nut Shelling equipment for the Jatropha fruits. See also, in Dutch: http://www.strohalm.nl/everts.html

Oil extraction is the main activity of the seed processing unit. In order to facilitate the extraction of oil from various seed types produced by the members of BYSA, preference was given to a press screw (endless pattern), of low production capacity for different reasons.

 

This type of press is more suitable for mobile systems and has the advantage of being more flexibility when fed with different seeds.
In order to achieve genuine local capacity in the maintenance and repair of the oil press, the project decided to design a model which can easily be manufactured in Yoro, Honduras.

 

Joost Fokkink developed a detailed design of an endless screw press that has been used as a model to manufacture the oil press in Yoro, Honduras. For more information about the design of the oil press, please contact Joost Fokkink (info@plantaardige-olie.nl).

Technicians from CEVERand MEFRAN (Franco Machinery) were trained on how to manufacture different parts of the oil press.

Cost Analisys

As shown in the table below, the cost of materials for the manufacture of an oil press- excluding  labor cost, is about  €1 485. A locally manufactured oil press is considered to be more cost effective when compared with imported models.
Comparatively, the cost of an oil press imported from Europe, with the same capacity would cost about €2 850 shipping cost.

 

Descripción

	Proveedor/ fabricante	Costo (Lps)	Cantidad	Total
motor	BOMOHSA	2 836	1	2 836
reductor	REPRIN	4 000	1	4 000
end part	CEVER
conection
		CEVER
Press cover
		CEVER
bearing6308
						275			1		275
Welding rod 308				13,5			11		149
Screws3/8x1				8			4		32
Screws3  + washer				12							119
Screw 35/16x1
				5			6		30
Screws 1/8 por 3/4				3			6		18
Hub AN
		REPRIN					2
Axles
	REPRIN				3			1 500
Pulley 1bq74
		COGACSA		555	1	555
Pulley 1bq36	COGACSA	289	1	289
Hub for pulley SDSX 3/4	COGACSA	175	1	175
Hub for pulley  SDSX 5/8	COGACSA	150	1	150
Band Dayco AP48	COGACSA	80	1	80
Bearing NBR 6308-2RS	COGACSA	90	1	90
Subtotal
				10 297
Press enclosure
		MEFRAN					1
Press parts
		MEFRAN					1
Head
	MEFRAN				1			19 000
Screw	Joost Fokkink				1			13 775
Total lempriras
				43 072
Total Dólares												2 279
Total Euros
												1 485

 

 

 

 

 

Extraction Results

 

 

Initial oil extraction trials illustrated the following results:

 

Jatropha

 

Capacity 8.5 kg per hour

 

2.8 liters per hour (with sediment) = 29% (based on mass%)

 

2.2 liters per hour (without  sediment) = 22.8% (mass)

 

Castor Bean

 

13 kg per hour

 

6.2 liters per hour (with sediment)

 

28.7% extraction

 

After necessary adjustments are made, subsequent presses of a greater capacity (up to 200 kg per hour) shall be built using the same design.

 

 

 Prototypes of the main part ( head) of the oilpress produced by CEVER

 

 

It is worth noting that, the presence of oil in the cake (residue from the pressed oilseeds) is an advantage for the biogas component. Therefore, viewing the production chain as an integrated process, a more efficient and expensive oil press shall obviously not be the best option in this situation.  For example, if the cost of extracting the last 5% of oil contained in the seeds is very high, it may be more advantageous to exploit the oil in the cake for biogas production. More clarity is expected on this analysis in 2009, when the Biogas component shall be integrated.

 

Another important point which must be taken into consideration is the antagonism between the quality and quantity of oil extracted.

 

In order to exploit the oil as a PPO, it is important to carry out cold extraction because it reduces the viscosity of the oil produced. Extraction using solvents and heat can increase yield, but it equally reduces the quality of the PPO fuel. Trials to determine optimal extraction shall be performed during the life of the project.

 

BYSA shall handle the production of two distinct types of oil:

 

• Edible oils, which shall include oil extracted from soybean, sesame, sunflower, canola and forage turnips. The oil extracted shall be sold primarily on the local market and secondarily in external markets- in exceptional cases of overproduction and better prices.

 

In restaurants and local agribusinesses, possibly, an agreement shall be negotiated for the re-purchase of used oil. Recollected used oil shall serve as a raw material for the processing of biodiesel.

 

• Non-edible oil, mainly oil extracted from Jatropha and Castor Bean, to be used predominantly as a biofuel locally.

 

 In the case of oil extracted from Castor Bean, it can be viewed as a medium-term investment for industries that shall use this oil as an input for the manufacture of biodegradable plastics, lubricants and paint components.

Main institutions involved in the extraction sub-component are:

 

BYSA (implementation and marketing)

 

FUNDER (business development)

 

CEVER (manufacture and maintenance of presses)

 

Joost Fokkink (technical support)

 

STRO (facilitating North-South exchange)